Bacteriological Profiles and Antimicrobial Susceptibility Patterns Among Isolates in Tonsillitis Patients Attending a...

Tonsillitis, primarily affecting children, is an inflammation of the pharyngeal tonsils caused by bacterial pathogens such as Staphylococcus aureus and Streptococcus pyogenes or viral agents. It can be classified as acute, chronic, or recurrent based on episode duration and frequency. Effective treatment requires identifying causative pathogens and assessing antibiotic resistance patterns. This study aims to update the bacterial isolates and antibiotic resistance of tonsillitis pathogens to support empirical treatment strategies and inform infection control policies.

This research was undertaken to assess the bacterial profiles and antibiotic susceptibility patterns of isolates obtained from tonsillitis patients.

This research was undertaken in the Department of Microbiology at Krishna Institute of Medical Sciences, Krishna Hospital and Medical Research Centre, Karad, District Satara, during the period from November 2022 to November 2023. Specimen collection and processing were performed following standard guidelines. Tonsillar swabs were collected and processed for pathogen isolation and identification using Gram staining and various biochemical tests; the susceptibility to antimicrobials was tested using the Kirby-Bauer disc diffusion method on Mueller-Hinton agar in accordance with Clinical and Laboratory Standards Institute 2022 recommendations.

Out of 105 clinically confirmed tonsillitis cases, 93 (88.57%) were culture-positive, with three cases presenting two isolates each, resulting in a total of 96 isolates, and 12 cases (11.43%) were culture-negative. A greater prevalence was noted among male patients (56 (60.21%)), with the highest occurrence observed in the 0-20-year age group (60 (64.51%)). Among the 96 isolates, 52 (54.16%) were Gram-negative and 44 (45.83%) were Gram-positive. The predominant isolate identified was S. aureus (39 (40.62%)), followed by Pseudomonas aeruginosa (19 (19.79%)). Testing for antimicrobial susceptibility revealed that S. aureus was the most common isolate, showing sensitivity to chloramphenicol in 38 cases (97.43%), while P. aeruginosa ,  the second most common isolate,  showed the highest sensitivity to azithromycin in 17 cases (89.47%).

Among 105 clinically confirmed tonsillitis cases, 93 were culture-positive, resulting in 96 isolates. S. aureus was the organism found most frequently, which showed maximum sensitivity to chloramphenicol, followed by P. aeruginosa, which is sensitive to azithromycin. Azithromycin, a macrolide, and chloramphenicol, a broad-spectrum antibiotic, both block bacterial protein synthesis via various mechanisms. This emphasizes the critical importance of analyzing bacterial profiles and resistance patterns to guide antimicrobial stewardship in tonsillitis management.